NOBODY catches much fish around the island of Arran now: overfishing and pollution have hit wild populations hard. There are still plenty of fish, mind: not free-swimming, but cooped up in huge salmon farms that leach detritus, pesticides, antibiotics and plastic waste into the Firth of Clyde.

And yet it is to Arran that Scotland’s coastal communities have turned to see a working vision of a cleaner, healthier, more productive ocean.